Method for controlling a piezoelectric drive unit

Abstract

The invention relates to a method for controlling a piezoelectric drive unit ( 81 ). For this purpose, a first control signal is applied to a first electrode ( 90 a ) of the first piezo element ( 95 ) of the piezoelectric drive unit ( 81 ). Additionally, a second control signal is applied to a second electrode ( 90 b ) of the first piezo element ( 95 ) of the piezoelectric drive unit ( 81 ). The first control signal is configured as a continuous positive first voltage signal. The second control signal is configured as a constant second voltage signal. The first control signal is always greater than the second control signal.

1 - 18 . (canceled) 
     
     
         19 . A method for controlling a piezoelectric drive unit, the method comprising the following steps:
 applying a first control signal to a first upper electrode of a first piezo element of the piezoelectric drive unit; and   applying a second control signal to a second lower electrode of the first piezo element of the piezoelectric drive unit;   wherein the first control is configured as a continuous, positive first voltage signal, and the second control signal is configured as a constant second voltage signal, the first control signal always being greater than the second control signal.   
     
     
         20 . The method as recited in  claim 19 , wherein the first control signal is generated by an ASIC. 
     
     
         21 . The method as recited in  claim 20 , wherein the positive first voltage signal is composed of a constant, positive third voltage signal and a periodically progressing positive fourth voltage signal. 
     
     
         22 . The method as recited in  claim 21 , wherein the constant, positive third voltage signal is applied to a voltage reference point of the ASIC. 
     
     
         23 . The method as recited in  claim 21 , wherein the constant, positive third voltage signal is applied to an analog front end of the ASIC. 
     
     
         24 . The method as recited in  claim 21 , wherein the constant, positive third voltage signal is generated by a first constant voltage source. 
     
     
         25 . The method as recited in  claim 19 , wherein the second control signal is constant at 0 V. 
     
     
         26 . The method as recited in  claim 19 , wherein the second control signal is generated by a second external, constant voltage source, the constant second voltage signal having a constant negative voltage. 
     
     
         27 . The method as recited in  claim 19 , wherein the first voltage signal progresses periodically, in sinusoidal or rectangular or parabolic fashion. 
     
     
         28 . The method as recited in  claim 19 , wherein the method is used for controlling a piezoelectric drive unit of a micromirror. 
     
     
         29 . The method as recited in  claim 28 , wherein the piezoelectric drive unit has a first wing pair and a second wing pair, the first piezo element being configured as a first PZT layer including the first electrode and the second electrode, the first PZT layer being situated only on the first or the second wing pair. 
     
     
         30 . The method as recited in  claim 29 , wherein the piezoelectric drive unit of the micromirror additionally has a second PZT layer as a second piezo element including a third upper electrode, and a fourth lower electrode, the first PZT layer being situated on the first wing pair and the second PZT layer being situated on the second wing pair, and the method further comprises:
 applying a third control signal to the third upper electrode of the second PZT layer; and   applying a fourth control signal to the fourth lower electrode of the second PZT layer;   wherein the third control signal is configured as a continuous, positive fifth voltage signal, and the fourth control signal is configured as a constant sixth voltage signal, the third control signal always being greater than the fourth control signal.   
     
     
         31 . The method as recited in  claim 30  wherein the positive first voltage signal and the positive fifth voltage signal progress in a temporally offset manner, the temporal offset being 180° relative to each other. 
     
     
         32 . A circuit configuration for controlling a piezoelectric drive unit, comprising:
 a first signal-generating unit configured to generate a first control signal for a first upper electrode of a first piezo element of the piezoelectric drive unit; and   a second signal-generating unit configured to generate a second control signal for a second lower electrode of the first piezo element of the piezoelectric drive unit;   wherein the first signal-generating unit is configured to generate the first control signal in such a way that the first control signal is configured as a continuous, positive first voltage signal, and the second signal-generating unit is configured to generate the second control signal in such a way that the second control signal is configured as a constant second voltage signal, the first control signal always being greater than the second control signal.   
     
     
         33 . The circuit configuration as recited in  claim 32 , wherein the first signal-generating unit is configured as an ASIC. 
     
     
         34 . The circuit configuration as recited in  claim 33 , further comprising:
 a third, constant voltage source which is connected to the ASIC and generates a constant seventh voltage signal, the ASIC generating from the constant seventh voltage signal a periodically progressing positive fourth voltage signal; and   a first constant voltage source which is connected to the ASIC and generates a constant, positive third voltage signal;   wherein the positive first voltage signal is composed of the third voltage signal and the fourth voltage signal.   
     
     
         35 . The circuit configuration as recited in  claim 32 , wherein the circuit configuration further comprises a second constant voltage source configured to generate the second control signal, the constant second voltage signal having a constant negative voltage. 
     
     
         36 . A micromechanical oscillating system, comprising:
 a micromirror;   a piezoelectric drive unit of the micromirror; and   a circuit configuration configured to control the piezoelectric drive unit, the circuit configuration including:
 a first signal-generating unit configured to generate a first control signal for a first upper electrode of a first piezo element of the piezoelectric drive unit, and 
 a second signal-generating unit configured to generate a second control signal for a second lower electrode of the first piezo element of the piezoelectric drive unit, 
 wherein the first signal-generating unit is configured to generate the first control signal in such a way that the first control signal is configured as a continuous, positive first voltage signal, and the second signal-generating unit is configured to generate the second control signal in such a way that the second control signal is configured as a constant second voltage signal, the first control signal always being greater than the second control signal.